Safety paper and method of making same



and methods of making such safety paper.

Patented June 29, 1937 ,.SAFETY PAPER. AND

ration of New Jersey' No Drawing.

This invention relates to safety paper including fraud preventing. writing material made of .paper or other substance or composition adapted for the printing or lithographing or for the inscription of writing or other mark or legend thereon and for use for example in the manufacture of checks, drafts, bonds, stock certificates or other instruments which it is desired to have protected against fraudulent, alteration This invention relates primarily to safety paper having incorporated therein by impregnation or superficial application either continuously or locally a chemical compound which is adapted upon application of a chemical ink eradicator the safety paper by the use of a chemical ink eradicator.

It is the purpose of this invention to'aiford chemicals which when incorporated in safety paper develop disfiguring stains of a particularly vivid and permanent character upon the application of a chemical ink eradicator thereto. It is a further purpose of this invention to aiford a chemical which when incorporated in safety paper does not discolor undesirably on aging due to premature development of color as the result of such causes as exposure to air and/or to light.

I have found that protection of a very desirable type can be afl'orded in safety paper by incorporating therein a mono-nitrogen substituted naphthylamine. Such compounds when incorporated in safety paper and treated with a bleach type of ink eradicator such as the ink eradicators extensively used at the present time containing hypochlorite solution or bleaching powder adapted to give up free chlorine, have beeniound to develop colors which are very vivid and give a very pronounced indication that attempt has been made to alter the safety paper. The colors so developed are likewise of a relatively permanent character as they are resistant to acids and alkalis and to reducing agents. Likewise such chemical compounds have been found to be highly stable on aging, that is, they do not tend to change color upon standing and/or exposure to light. Moreover, many of such substances are substantially colorless, that is, they do not tend to impart noticeable color to safety paper in which they are incorporated in proportions desirable for developing'warning color indicia in the "safety paper upon the application color.

METHOD or MAKING AME Francis L. Simons, Needham, Mass, assignor to George La Monte & Son, Nutley, N. J., a corpo- Application February 4. 1935 Serial No. 4,872

sclaims. (01. 91-6195) of a chemical ink eradicator thereto.- In this connection it may be stated that development of color includes change from a colorless substance to' a colored substance, intensification of color or change from one color to another color.

.In the usual case the materials mentioned above change from a substantially colorless state or very slightly colored state to a very pronounced Normally it is regarded as preferable to employ substantially colorless compounds adapt"-- ed to exhibit a decided color development when treated ,with a chemical ink eradicator.

By mono-nitrogen substituted naphthylamine it is meant that one only of the hydrogen atoms in the amino group has been replaced by an allphatic, heterocyclic or aromatic substituent.

The formulae for naphthylamine may be written in either of the following ways, namely,

A more condensed formula covering both the alpha and beta naphthylamines may be written as follows: 7

wherein One'R radical is the radical NH: and

the remaining R radicals are hydrogen. The alpha '(or) and beta (5) positions have been indicated in the general formula and it is apparent that the NIH group'can occupy either an a or 5 position. x

In mono-nitrogen substituted 'naphthylamines the NH2 group becomes the group aliphatic, aromatic, or heterocyclic X being any 1 that a hydrogen atom of the hydrocarbon radical is replaced by an acidic radical such'as SOzH (sulphonic); NO: (nitro); COOH (carboxyl), or

a Cl, Br or I (halogen); For the purposes herein set forth the OH (hydroxyl) radical may be included in the acidic group. "I'h8 salts of such acidic derivatives are'the salts of alkali metals e. g. sodium and potassium and other salt forming alkaline earth and heavy metals. The term salt also includesorganic salts or esters such as methyl, ethyl, phenyl, etc. By basic derivative it is understood that a hydrogen atom of the hydrocarbon radical is replaced by a basic radical such as NHa (amino). These basic derivatives form ammonium type salts such as the sulphates, hydrochlorides, acetates, oxalates, and t e like.

In mono-nitrogen substituted naph hyJamines which may be used according to. this invention,

the R radicals other than the radical may be not only hydrogen but also an aliphatic, aromatic or heterocyclic substituent as above defined. Moreover, the mono-nitrogen substituted naphthylamines which may be used in the practice of this invention may include more radical in mono-nitrogen substituted naphthylamines may be an acidic; radical or a salt thereof or a basic radical or a salt thereof as above described only in such case the radical or radicals are attached directly to one or more carbon atoms of the naphthyl nucleus instead of to a carbon atom of a hydrocarbon substituent.

Mono-nitrogen substituted naphthylamines as referred to herein, include salts thereof such as the sulphates, hydrochlorides, oxalates, acetates and the like which salts may likewise be employed in the practice 'of this invention.

Certain mono-nitrogeh-substituted naphthylamines which are preferably employed in the practice of this invention may be indicated by the formula R R wherein one R radical is X being any aliphatic, aromatic, or heterocyclic substituent. Preferably X is'a hydrocarbon radical and of the hydrocarbon radicals aromatic and heterocyclic radicals are'further to be preferred. It is likewise preferable that the remaining R radicals be any radical selected from the group consisting of x as above defined, hydrogen, hydrocarbon radicals, acidic derivatives of hydrocarbon radicals, salts of said acidic derivatives, basic derivatives of said hydrocarbon radicals, salts of said basic derivatives, acidic radicals, salts of ,said acidic radicals, basic radicals, and salts of said basic radicals. As above mentioned, the mono-nitrogen substituted naphthylamines which may be employed in the practice of this invention also includes salts formed with the basic In the foregoing description the hydrocarbon radicals may be radicals such as methyl, ethyl,

propyl, etc., as well as aromatic radicals such as phenyl, naphthyl, tolyl, etc. and heterocyclic radicals .are pyridyl, pyryl, quinolyl, etc. It is not regarded as necessary to list the names of substituted naphthylamines having such radicals. In the case of the phenyl radical, for example, as contained in mono-nitrogen substituted naphthylamine the name of the compound is.N-phenyl-alpha naphthylamine or N-phenylbeta-naphthylamine, the N symbol indicating that the phenyl is attached to the N atom of the naphthylamine. The same applies in applying nomenclature to substituted naphthylamines containing other radicals above mentioned.

Referring to acidic substituents and acidic derivatives of hydrocarbon substituents the sulphonic and carboxyl derivatives are preferred.

Also the alkali metal salts e. a. sodium or potas slum of acidic derivatives are preferred where water solubility isdesired.

The preparation of safety paper embodying this invention can be practiced in several ways. The naphthylamines above mentioned which areinsoluble in water may be incorporated in safety paper by mixing the same with the paper fibre during the beating operation which forms a. step in the paper; making process. The chemical may be added in the form of a dry powder, for example, as the chemicals above mentioned are very stable and will not be altered during the beating operation or during the subsequent steps of the paper making process. The chemical compoundln such case is carried down into the finished paper so that when attempt is made to alter a legend on the paper by using a. chemical ink eradicator such as a bleach, the paper will develop a pronounced color which affords a warning indicia. In the case of the N-phenyl-naphthylamines, and other naphthylamines of an analogous character about 2% to 10% of the chemical on the dry weight of the paper may be used. Of course, greater or lesser amounts can be used, depending on the amount of color developed by the application of a chemical ink eradicator to the substance selected and the intensity of color that is desired in the warning stain. Normally, the greater the amount of safety chemice] in safety paper, the more intense will be the color that is developed when a chemical bleaching material is applied to the safety paper.

Alternately, the safety chemical may be dis- .5 solved in a suitable solvent therefor. Thus many of the. mono nitrogen substituted naphthylamines above mentioned are soluble in solvents, such as acetone, ethyl alcohol, benzene and the like or mixtures thereof. A solution of the safety chemical may be applied in any suitable manner as by dipping, spraying, etc. The concentration of the solution is preferably such that about 2% to 10% ofrthe chemical on the weight of the paper will beretained after the solvent has been evaporated from the paper. When a water solu ble naphthylamine derivative is used water may be used as a solvent. The safety chemicals by the methods above described or by any other method of i pregnation or surface application, can be impregn ted in the body of the safety paper or may be applied to the surface thereof and while it is preferable to have all parts of the safety paper react similarly to chemical ink eradicators due to the uniform distribution of the safety chemical therein, the

safety chemical can be applied locally as by printing or other suitable method. In any event, safety paper carrying a safety chemical herein described is to be'regarded as having any 'such 3 safety chemical incorporated therein. It will be understood that this invention is applicable among other fields of application in' connection with-plain white paper as well as tinted paper Patent No. 2,085,675.

. FRANCIS L. SIMONS Certificate of Correction or paperhaving surface markings thereon. It is likewise applicable when a tint in the paper is delible under the action of chemical ink eradicators and/or when the surface marking or tinting is removable by mechanical erasure. Y

While this invention has been described in connection with certain specific examples thereof, it is to be understood that this has been done merely for the purpose of illustration and that the scope 'of this invention is to be governed by the following claims.

I claim:

- 1. A safety paper having incorporated therein a mono-nitrogen substituted naphthylamine.

2. A safety paper having incorporated therein Nphenyl-naphthylamine.

3. A safety paper having incorporated therein N phenyl naphthylamine sulphonic acid.

4. A safety paper having incorporated therein N phenyl amino naphthylamine.

5. A method of making safety paper which comprises incorporating in paper N-phenyl naphthylamine.

6. A method of making safety paper which comprises incorporating in paper N-phenyl naphthylamine sulphonic acid.

7. A method of making safety paper which comprises incorporating in paper N-phenyl amino naphthylamine.

8. A method of making comprises incorporating in paper a mono-nitrogen substituted naphthylamine. I

FRANCIS L. SIMONS.

June 29, 1937.

It is hereby certified that error appears in the v I v printed specification of the above numbered patent reqmr ng correction as follows: Page 2, first column, line 45, for the formula v H I 9/2 x read: I

and that the said Letters Patentsh ould be read 'th I I ereln' I same may conform to the record of the case in th Patent ill i bi th that. the

and sealed this 1stv day of M'arch, A. D. 1938.

HENRY vAN ARSDALE, d'mg Commissioner of Patents.

safety paper which ice] in safety paper, the more intense will be the color that is developed when a chemical bleaching material is applied to the safety paper.

Alternately, the safety chemical may be dis- .5 solved in a suitable solvent therefor. Thus many of the. mono nitrogen substituted naphthylamines above mentioned are soluble in solvents, such as acetone, ethyl alcohol, benzene and the like or mixtures thereof. A solution of the safety chemical may be applied in any suitable manner as by dipping, spraying, etc. The concentration of the solution is preferably such that about 2% to 10% ofrthe chemical on the weight of the paper will beretained after the solvent has been evaporated from the paper. When a water solu ble naphthylamine derivative is used water may be used as a solvent. The safety chemicals by the methods above described or by any other method of i pregnation or surface application, can be impregn ted in the body of the safety paper or may be applied to the surface thereof and while it is preferable to have all parts of the safety paper react similarly to chemical ink eradicators due to the uniform distribution of the safety chemical therein, the

safety chemical can be applied locally as by printing or other suitable method. In any event, safety paper carrying a safety chemical herein described is to be'regarded as having any 'such 3 safety chemical incorporated therein. It will be understood that this invention is applicable among other fields of application in' connection with-plain white paper as well as tinted paper Patent No. 2,085,675.

. FRANCIS L. SIMONS Certificate of Correction or paperhaving surface markings thereon. It is likewise applicable when a tint in the paper is delible under the action of chemical ink eradicators and/or when the surface marking or tinting is removable by mechanical erasure. Y

While this invention has been described in connection with certain specific examples thereof, it is to be understood that this has been done merely for the purpose of illustration and that the scope 'of this invention is to be governed by the following claims.

I claim:

- 1. A safety paper having incorporated therein a mono-nitrogen substituted naphthylamine.

2. A safety paper having incorporated therein Nphenyl-naphthylamine.

3. A safety paper having incorporated therein N phenyl naphthylamine sulphonic acid.

4. A safety paper having incorporated therein N phenyl amino naphthylamine.

5. A method of making safety paper which comprises incorporating in paper N-phenyl naphthylamine.

6. A method of making safety paper which comprises incorporating in paper N-phenyl naphthylamine sulphonic acid.

7. A method of making safety paper which comprises incorporating in paper N-phenyl amino naphthylamine.

8. A method of making comprises incorporating in paper a mono-nitrogen substituted naphthylamine. I

FRANCIS L. SIMONS.

June 29, 1937.

It is hereby certified that error appears in the v I v printed specification of the above numbered patent reqmr ng correction as follows: Page 2, first column, line 45, for the formula v H I 9/2 x read: I

and that the said Letters Patentsh ould be read 'th I I ereln' I same may conform to the record of the case in th Patent ill i bi th that. the

and sealed this 1stv day of M'arch, A. D. 1938.

HENRY vAN ARSDALE, d'mg Commissioner of Patents.

safety paper which 

